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update lower bounds from feasible solutiosn

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2013-12-07 22:09:57 -08:00
parent e307c5fdda
commit 370a4b66de
14 changed files with 123 additions and 44 deletions
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47
src/opt/opt_context.cpp
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@ -85,6 +85,7 @@ namespace opt {
return is_sat;
}
s.get_model(m_model);
update_lower();
switch (m_objectives.size()) {
case 0:
return is_sat;
@ -223,11 +224,15 @@ namespace opt {
rational coeff(0);
// minimize 2*x + 3*y
// <=>
// (assret-soft (not x) 2)
// (assert-soft (not x) 2)
// (assert-soft (not y) 3)
//
if (get_pb_sum(term, terms, weights, coeff) && coeff.is_zero()) {
// TBD: and weights are positive?
for (unsigned i = 0; i < weights.size(); ++i) {
if (!weights[i].is_pos()) {
return false;
}
}
for (unsigned i = 0; i < terms.size(); ++i) {
terms[i] = m.mk_not(terms[i].get());
}
@ -348,6 +353,40 @@ namespace opt {
}
}
void context::update_lower() {
arith_util a(m);
expr_ref val(m);
rational r(0);
for (unsigned i = 0; i < m_objectives.size(); ++i) {
objective const& obj = m_objectives[i];
switch(obj.m_type) {
case O_MINIMIZE:
case O_MAXIMIZE:
if (m_model->eval(obj.m_term, val) && a.is_numeral(val, r)) {
m_optsmt.update_lower(obj.m_index, r);
}
break;
case O_MAXSMT: {
bool ok = true;
for (unsigned j = 0; ok && j < obj.m_terms.size(); ++j) {
if (m_model->eval(obj.m_terms[j], val)) {
if (!m.is_true(val)) {
r += obj.m_weights[j];
}
}
else {
ok = false;
}
}
if (ok) {
m_maxsmts.find(obj.m_id)->update_lower(r);
}
break;
}
}
}
}
void context::display_assignment(std::ostream& out) {
for (unsigned i = 0; i < m_objectives.size(); ++i) {
objective const& obj = m_objectives[i];
@ -459,6 +498,10 @@ namespace opt {
if (m_solver) {
m_solver->collect_statistics(stats);
}
map_t::iterator it = m_maxsmts.begin(), end = m_maxsmts.end();
for (; it != end; ++it) {
it->m_value->collect_statistics(stats);
}
}
void context::collect_param_descrs(param_descrs & r) {